2013: Tesla CEO responds to concerns over fire in one of its Model S vehicles

For the second time this year, Tesla CEO Elon Musk has come out swinging.

In the same week that a video of a Model S on fire went viral, pulling the company's share price down sharply for two days, Musk on Friday took to the blogosphere to defend his electric sedan. And his website post claiming that his vehicles are far less prone to fires than gasoline-powered cars cheered investors, who pushed Tesla stock back up more than 4 percent.

Coming to the defense of his fledging electric-car startup is becoming something of a routine for Musk, who last February aggressively went after The New York Times for what he said was a false story claiming the Model S falters in cold weather. Back then, as it did this week, the company's stock took a big hit from the negative news. Musk attacked the Times' reporting, calling its finding "fake," while the Times fired back saying his allegation was "flatly untrue."

This time, after the video of Tuesday's fire on a Washington state highway spread like wildfire around the Web and Tesla's high-flying shares plummeted 6 percent Wednesday and more than 4 percent Thursday, Musk launched a personal campaign of damage control.

The CEO blogged that this was the first fire to hit one of his sedans while gas-powered car fires are relatively common.

"There are 150,000 car fires per year according to the National Fire Protection Association, and Americans drive about 3 trillion miles per year, according to the Department of Transportation," Musk wrote. "That equates to 1 vehicle fire for every 20 million miles driven, compared to 1 fire in over 100 million miles for Tesla."

The blog post also went into great detail on the incident that sparked the fire, explaining that a large metal object, believed to be part of a large truck, struck the bottom of the Model S with unusual force that pierced the armor plate protecting the car's battery pack. Musk also stressed that the safeguards in the battery pack kept the fire from spreading to the passenger enclosure.

"Had a conventional gasoline car encountered the same object on the highway, the result could have been far worse," the CEO wrote in his blog. "A typical gasoline car only has a thin metal sheet protecting the underbody, leaving it vulnerable to destruction of the fuel supply lines or fuel tank, which causes a pool of gasoline to form and often burn the entire car to the ground."

One analyst earlier told this newspaper that the fire could discourage potential buyers.

"With new technologies such as lithium ion batteries, there's heightened awareness around a fire,'' RW Baird research analyst Ben Kallo said Thursday, adding that fears could make potential customers for the Palo Alto-based company wait even longer to make a purchase. Wednesday morning Kallo had issued a downgrade for Tesla stock to "neutral" from "outperform."

Musk's blog post included an email from Robert Carlson, whose Model S had caught fire, in which the owner seems to downplay the entire incident, which he suggested looked a lot worse in the Internet version than it did in reality.

"The batteries went through a controlled burn which the Internet images really exaggerates," Carlson wrote. "Anyway, I am still a big fan of your car and look forward to getting back into one. I am also an investor and have to say that the response I am observing is really supportive of the future for electric vehicles."

Tesla's Model S has been the most important factor in the company's booming Wall Street success in 2013, with successful sales allowing Musk to announce its first profitable quarter and pay off the federal government's loan much earlier than expected. Shares resumed their upward trajectory Friday, gaining 4.4 percent to $180.98.

Staff writer Jeremy Owens contributed to this report. Contact Patrick May at 408-920-5689; follow him at Twitter.com/patmaymerc.